Elasticsearch入门

安装

Linux安装示例

• 1. 下载

curl -L -O https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-7.2.0-linux-x86_64.tar.gz

• 2. 解压

tar -xvf elasticsearch-7.2.0-linux-x86_64.tar.gz

• 3. 配置
     配置文件位于config/elasticsearch.yml，部分配置说明如下：
  • cluster.name 集群名称，以此作为是否同一集群的判断条件
  • node.name 节点名称，以此作为集群中不同节点的区分条件
  • network.host/http.port 网络地址和端口，用于http和transport服务使用
  • path.data 数据存储地址
  • path.log 日志存储地址
    修改参数的第二种方式
    启动时在启动命令后跟需要修改的参数信息，如下：

./elasticsearch -Ecluster.name=my_cluster_name -Enode.name=my_node_name

• 3. 单节点启动

# 前台启动
/bin/elasticsearch
# 后台运行
/bin/elasticsearch -d

• 4. 简单集群启动

bin/elasticsearch -Ehttp.port=9200 -Epath.data=master -Enode.name=master
bin/elasticsearch -Ehttp.port=9201 -Epath.data=slave_1 -Enode.name=node_salve_1
bin/elasticsearch -Ehttp.port=9202 -Epath.data=slave_2 -Enode.name=node_salve_2

集群管理

Elasticsearch提供了一个非常全面和强大的REST API，可以使用它与集群进行交互。使用API可以完成以下操作：

• 检查群集，节点和索引运行状况，状态和统计信息
• 管理您的群集，节点和索引数据和元数据
• 对索引执行CRUD（创建，读取，更新和删除）和搜索操作
• 执行高级搜索操作，例如分页，排序，过滤，脚本编写，聚合等等

REST API

健康检查

kibana console

GET /_cat/health?v

curl

curl -XGET "http://localhost:9200/_cat/health?v"

响应

epoch      timestamp cluster    status node.total node.data shards pri relo init unassign pending_tasks max_task_wait_time active_shards_percent
1564112148 03:35:48  es-cluster green           3         3     10   5    0    0        0             0                  -                100.0%

• status
  • Green：一切都很好（集群功能齐全）
  • Yellow：所有数据都可用，但尚未分配一些副本（群集功能齐全）
  • Red：某些数据由于某种原因不可用（群集部分功能）
    注意：当群集为Red时，它将继续提供来自可用分片的搜索请求，但您可能需要尽快修复它，因为存在未分配的分片。

查看节点信息

kibana console

GET /_cat/nodes?v

curl

curl -XGET "http://localhost:9200/_cat/nodes?v"

响应

ip        heap.percent ram.percent cpu load_1m load_5m load_15m node.role master name
127.0.0.1           16          98  16    2.97                  mdi       -      node_salve_2
127.0.0.1           20          98  16    2.97                  mdi       *      master
127.0.0.1           27          98  16    2.97                  mdi       -      node_salve_1

创建索引

kibana console

PUT /user

curl

curl -XPUT "http://localhost:9200/user"

响应

{
	"acknowledged": true,
	"shards_acknowledged": true,
	"index": "user"
}

列出所有索引信息

kibana console

GET /_cat/indices?v

curl

curl -XGET "http://localhost:9200/_cat/indices?v"

响应

health status index                uuid                   pri rep docs.count docs.deleted store.size pri.store.size
green  open   user             pmN9spFrQautZJI-xym1QA   1   1          0            0       460b           230b

• pri 主分片数
• rep 副本数

创建文档

kibana console

PUT /user/_doc/1
{
  "name": "white colde",
  "age":18
}

curl

curl -XPUT "http://localhost:9200/user/_doc/1" -H 'Content-Type: application/json' -d'{  "name": "white colde",  "age":18}'

1为文档的唯一id，可不指定，当不指定时，系统会随机生产一个字符串作为文档的id

响应

{
  "_index" : "user",
  "_type" : "_doc",
  "_id" : "1",
  "_version" : 1,
  "result" : "created",
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 0,
  "_primary_term" : 1
}

修改数据

• 方式一

kibana console

PUT /user/_doc/1
{
  "name": "white colde",
  "age":19
}

curl

curl -XPUT "http://localhost:9200/user/_doc/1" -H 'Content-Type: application/json' -d'{  "name": "white colde",  "age":19}'

此时id必须指定，如果id对应的文档不存在，则为新建

响应

{
  "_index" : "user",
  "_type" : "_doc",
  "_id" : "1",
  "_version" : 2,
  "result" : "updated",
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 1,
  "_primary_term" : 1
}

• 方式二

kibana console

POST /user/_update/1
{
  "doc":{
    "name":"whtie fisher",
    "age":21,
    "school":"uc"
  }
}

curl

curl -XPOST "http://localhost:9200/user/_update/1" -H 'Content-Type: application/json' -d'{  "doc":{    "name":"whtie fisher",    "age":21,    "school":"uc"  }}'

响应

{
  "_index" : "user",
  "_type" : "_doc",
  "_id" : "1",
  "_version" : 3,
  "result" : "updated",
  "_shards" : {
    "total" : 2,
    "successful" : 2,
    "failed" : 0
  },
  "_seq_no" : 2,
  "_primary_term" : 1
}

• 脚本更新

kibana console

POST /user/_update/1
{
  "script":"ctx._source.age+=5"
}

curl

curl -XPOST "http://localhost:9200/user/_update/1" -H 'Content-Type: application/json' -d'{  "script":"ctx._source.age+=5"}'

ctx._source指的是即将更新的当前源文档

查询文档

• 使用ID进行查询
  kibana console

GET /user/_doc/1

curl

curl -XGET "http://localhost:9200/user/_doc/1"

响应

{
  "_index" : "user",
  "_type" : "_doc",
  "_id" : "1",
  "_version" : 1,
  "_seq_no" : 0,
  "_primary_term" : 1,
  "found" : true,
  "_source" : {
    "name" : "white colde",
    "age" : 18
  }
}

删除索引

kibana console

DELETE /user

curl

curl -XDELETE "http://localhost:9200/user"

{
  "acknowledged" : true
}

批量操作

kibana console

POST /user/_bulk?pretty
# 指定id，如果当前索引中存在文档，则执行更新操作
{"index":{"_id":"1"}}
{"name":"colde1","age":21}
# 未指定id，系统随机生产一个字符串作为文档id
{"index":{}}
{"name":"colde2","age":28}
# 删除文档id为2的文档
{"delete":{"_id":"2"}}

curl

curl -XPOST "http://localhost:9200/user/_bulk?pretty" -H 'Content-Type: application/json' -d'{"index":{"_id":"1"}}{"name":"colde1","age":21}{"index":{}}{"name":"colde2","age":28}{"delete":{"_id":"2"}}'

响应

{
  "took" : 47,
  "errors" : false,
  "items" : [
    {
      "index" : {
        "_index" : "user",
        "_type" : "_doc",
        "_id" : "1",
        "_version" : 8,
        "result" : "updated",
        "_shards" : {
          "total" : 2,
          "successful" : 2,
          "failed" : 0
        },
        "_seq_no" : 19,
        "_primary_term" : 1,
        "status" : 200
      }
    },
    {
      "index" : {
        "_index" : "user",
        "_type" : "_doc",
        "_id" : "bDEQLWwBhMGMKE1AFwmS",
        "_version" : 1,
        "result" : "created",
        "_shards" : {
          "total" : 2,
          "successful" : 2,
          "failed" : 0
        },
        "_seq_no" : 20,
        "_primary_term" : 1,
        "status" : 201
      }
    }
  ]
}

搜索文档

匹配所有文档

• 方式一

kibana console

GET /user/_search?q=*&sort=age:desc&size=10&from=0

curl

curl -XGET "http://localhost:9200/user/_search?q=*&sort=age:desc&size=10&from=0"

请求说明

• q 需要匹配的关键字
• sort 排序字段
• size 返回Y条数据
• from 跳过前X条数据
• 匹配所有文档方式二

kibana console

GET /user/_search
{
  "query": { "match_all": {} },
  "size":10,
  "from":0,
  "sort": [
    { "age": "asc" }
  ]
}

curl

curl -XGET "http://localhost:9200/user/_search" -H 'Content-Type: application/json' -d'{  "query": { "match_all": {} },  "size":10,  "from":0,  "sort": [    { "age": "asc" }  ]}'

响应

{
  "took" : 0,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 3,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [
      {
        "_index" : "user",
        "_type" : "_doc",
        "_id" : "aTENLWwBhMGMKE1ArAnX",
        "_score" : null,
        "_source" : {
          "name" : "white",
          "age" : 212
        },
        "sort" : [
          212
        ]
      },
      {
        "_index" : "user",
        "_type" : "_doc",
        "_id" : "ajEOLWwBhMGMKE1ALAko",
        "_score" : null,
        "_source" : {
          "name" : "white",
          "age" : 212
        },
        "sort" : [
          212
        ]
      },
      {
        "_index" : "user",
        "_type" : "_doc",
        "_id" : "2",
        "_score" : null,
        "_source" : {
          "name" : "colde2"
        },
        "sort" : [
          9223372036854775807
        ]
      }
    ]
  }
}

响应说明

• took 执行搜索的时间（单位毫秒）
• timed_out 搜索是否超市
• _shards 搜索分片总量，搜索成功/失败分片的数量
• hits 搜索结果
  • hits.total 匹配搜索条件的文档总数
  • hits.hits 实际的搜索结果数组
  • hits.sort 为每个结果排序键的排序值
  • hits.hits._score 查询匹配度，分数越高，文档越相关，分数越低，文档的相关性越低。（此处未传入对应的匹配条件，_score未null）

指定返回字段

GET /user/_search
{
  "query": { "match_all": {} },
  "_source": ["name"]
}
# 相当于SQL
SELECT NAME FROM USER

返回source中只包含name，不显示age字段

{
   "_index" : "user",
   "_type" : "_doc",
   "_id" : "azEPLWwBhMGMKE1AvgkV",
   "_score" : 1.0,
   "_source" : {
     "name" : "colde3"
   }
}

匹配搜索查询

GET /user/_search
{
  "query": {
    "match": {
      "name": "white blank"
    }
  }
}

es首先会对匹配条件“white blank”进行分词，拆分为“white”和“blank”，最终返回包含white或blank的文档

短语匹配查询

GET /user/_search
{
  "query": {
    "match_phrase": {
      "name": "white blank"
    }
  }
}

match_phrase不会对匹配条件“white blank进行分词”，只会返回包含“white blank”这个短语的文档

bool查询

• must

GET /user/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "name": "white" } },
        { "match": { "name": "blank" } }
      ]
    }
  }
}

返回同时包含“white”和“blank”的文档

• should

GET /user/_search
{
  "query": {
    "bool": {
      "should": [
        { "match": { "name": "white" } },
        { "match": { "name": "blank" } }
      ]
    }
  }
}

返回包含“white”或“blank”的文档，等价于match white blank

• must_not

GET /user/_search
{
  "query": {
    "bool": {
      "must_not": [
        { "match": { "name": "white" } },
        { "match": { "name": "blank" } }
      ]
    }
  }
}

返回既不包含“white”也不包含“blank”的文档

• must and must_not

GET /user/_search
{
  "query": {
    "bool": {
      "must": [
        { "match": { "name": "white" } }
      ],
      "must_not": [
        { "match": { "age": 21 } }
      ]
    }
  }
}

返回name包含“white”并且age不等于21的文档

过滤器

范围查询

GET /user/_search
{
  "query": {
    "bool": {
      "must": { "match_all": {} },
      "filter": {
        "range": {
          "age": {
            "gte": 21,
            "lte": 29
          }
        }
      }
    }
  }
}

返回must匹配条件数据（这里是match_all）,在结果集中执行过滤器规则返回age大于等于21并且小于等于29的所有用户

聚合查询

GET /user/_search
{
  "size": 0,
  "aggs": {
    "group_by_state": {
      "terms": {
        "field": "name.keyword"
      }
    }
  }
}

返回统计同名用户数量

GET /user/_search
{
  "size": 0,
  "aggs": {
    "group_by_state": {
      "terms": {
        "field": "name.keyword"
      },
      "aggs": {
        "average_balance": {
          "avg": {
            "field": "age"
          }
        }
      }
    }
  }
}

返回统计同名用户数量和计算同名用户的平均年龄